Seam detector



May 26, 1970 R. L. DAVIDSON SEAM DETECTOR Filed Dec. 20, 1968 FIG. 2

FIG. I

INVENTOR.

RALPH L. DAVIDSON FIG. 3

ATTORNEYS United States Patent 3,514,558 SEAM DETECTOR Ralph L. Davidson, Worcester, Mass., assignor to Curtis & Marble Machine Co., Worcester, Mass., a corporation of Massachusetts Filed Dec. 20, 1968, Ser. No. 785,655 Int. Cl. B65h 25/14 US. Cl. 20061.14 12 Claims ABSTRACT OF THE DISCLOSURE The invention is a switching apparatus for detecting the presence of a seam in a moving web of textile fabric, plastic or paper without being operated by occasional imperfections or slubs in the material. A switch is stationed proximate to the material and is actuated by motion of a pair of feelers or rollers struck simultaneously by a seam. Non-simultaneous movement of either roller will not operate the switch.

BACKGROUND OF INVENTION In the processing of textile fabrics and other materials, for economy processing is done using long lengths of material, these long lengths being obtained by sewing together shorter lengths of the material. In such sewing, a scam is made which has a thickness greater than that of the material itself.

However, particularly for textile fabrics, it is eventually necessary to remove the seams in order to fold the shorter lengths or to wind them in bolts of cloth. Removal of the seam is generally done in a machine in which the web moves rapidly until the seam occurs. It is then necessary to stop the forward progress of the web when the seam occurs, so that the seam may be taken out.

Many machines have been devised to detect the occurrence of a seam as the cloth web moves rapidly along the apparatus, and then to actuate control means which will stop the above motion of the web at the proper place. In the machines hitherto known, the adjustment of the seam detecting apparatus is a rather precise one, because the seam may be only twice as thick as the cloth material itself, and the cloth material itself may be only a few thousandths in thickness. With such a precise setting, then unevenness in the material itself may cause nuisance stoppage of the flow of the web toward the bolting or folding apparatus.

Another difficulty is that particularly in connection with cloth materials, slubs may occur, and in presently known machinery, if one of the slubs strikes the actuating arm or feeler, the web will stop just as if a seam had been encountered. This again is a nuisance trip-out.

A third problem that occurs is that if in a web of material a seam occurs which runs longitudinally of the Web, and the machine is adjusted to be actuated merely by an increase in thickness of the material, then if a feeler should strike this longitudinal seam it will cause a nuisance tripout.

A fourth difiiculty is that the seam detecting apparatus must be able to sense the difference between the slub and a seam.

Therefore, it is the general purpose of this invention to provide apparatus for detecting the occurrence of a seam in a rapidly moving web of cloth or other material, which apparatus provides solutions for one or all of the above problems.

A particular object of the invention is to provide a seam detecting apparatus which actuates a web stopping means by a mechanical impulse being imparted to the seam detector, rather than by a relatively slow change in the position of a feeler.

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A still further object of the invention is to provide apparatus of the above kind which will not be actuated by slubs occurring in the material, and will be actuated only by a seam which extends transversely of the web of cloth.

Still another object of the invention is the provision of apparatus of the above kind in which a transversely extending seam will actuate the seam detecting apparatus, whereas a longitudinally extending seam or simple doubling of the thickness of the material of the web will not cause actuation.

Yet another object of the invention is the provision of apparatus of any of the above kinds in which means are incorporated to detect or indicate a seam, even though the machine has been stopped for other reasons and a seam occurs at or near the seam detecting apparatus.

Other objects and advantages of the invention will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, arrangement of parts, and manipulation of the apparatus all of which will be exemplified in the structures hereinafter set forth, and the scope of the application of which will be indicated in the appended claims.

DRAWINGS AND DISCLOSURE In the accompanying drawings, in which one of the various possible embodiments of the invention is illustrated:

FIG. 1 shows an elevation, partly in section, of one embodiment of this invention;

- FIG. 2 shows a plan view, partly in section, of the embodiment of FIG. 1; and

FIG. 3 is a plan view of the FIG. 1 embodiment, with a portion thereof removed in order to show more clearly p the construction of certain parts.

Throughout the drawings, similar reference characters indicate corresponding parts, and dimensions of certain of the parts as shown in the drawings may have been modified and/or exaggerated for the purposes of clarity of illustration and understanding of the invention.

Referring now to the drawings, the apparatus of this invention (indicated generally by numeral 2) is shown mounted on a beam such as a U-channel 4 which extends across a moving web 6 of the material in which a seam is to be detected. The apparatus 2 may be mounted conveniently on the beam 4 by means of a nut and bolt 8 which passes through both the base 10 and the beam as shown. It is also to be noted that by this kind of attachment, the base 10 may be rotated about the beam slightly in order to account for a slight angle that the seams in the web of material may make transversely of the web. Of course, if swiveling is not desired, a plurality of nuts and bolts may be used in conventional manner.

The web 6 traverses an anvil or plate 12 which is fastened to a base 14 of the entire apparatus.

Mounted on the base 10 are a pair of electrical switches 16 and 18 (such as, for example, those made by General Control Company, Type KE-D), attachment being made by conventional means. Switch 16 is actuated by a rotation of the rotary switch-actuating arm 20 to which is attached a movable switch lever 22. In like manner, switch 18 is actuated by its rotary switch arm 24 to which is attached a movable switch lever 26.

At the ends of the base plate 10 there are attached by conventional means a U-shaped clevis 30 at one end, and U-shaped clevis 32 at the other end. Rotatably mounted in clevis 30 by shaft 31 is the hub 34 of a bell crank having a vertical arm 36 and an arm 38 which extends diagonally downwardly toward the web 6. Each of the arms 36 and 38 may be conveniently screwed into tapped holes in the hub 34, and then locked in place by means of conventional lock nuts 39 as shown.

The other end of the arm 38 is screwed into an extension 40 of a swivel bearing member 42. For example, a swivel joint such as a Heim Type PIP-6C Unibal Spherical Rod End Bearing may be used. This swivel bearing contains an inner ball 44 which is adapted to receive a shaft 46. The latter is held at its center portion by means of the retaining collars 48. At the ends of the shaft 46 are provided seam feelers, these feelers comprising, in this instance, rollers 50 and 52 which are rotatably mounted at the ends of the shaft.

As thus described, it will be observed that the shaft 46 has 360" of free movement in the swivel bearing 42- 44. However, since it is desired to limit this freedom of motion somewhat, a U-shaped retaining member 54 is mounted by means of the clamp nut 56 to the end of extension 40, the arms of the member 54 bending outwardly and terminating adjacent the shaft 46 with a slight clearance being provided. In view of the angular relationship of the shaft 38 to the web 6, it will be observed that the shaft 46 and rollers 50 and 52 are thus prevented from moving substantially in a direction parallel to the web 6, but can freely move in a direction perpendicular to the web 6. That is, each of the rollers 50 and 52 has its motion so limited that it cannot move in a direction generally longitudinal of the web. The purpose of this construction is to make sure that if a seam occurs, it will strike both of the rollers 50-52 simultaneously or nearly simultaneously. If the shaft 46 were free to rotate in a plane parallel to the web 6, then a skew seam could strike first one roller and then the other roller, with resulting improper operation of the apparatus. If desired, means other than the U-shaped member 54 may be used in order to constrain the motion of the shaft 46.

Arm 36 projects upwardly through a hole 58 provided in the base 10, the hole being sufficiently large to permit free movement of the arm 36 therein when the swivel joint 42 is caused to move upwardly by motion of the rollers 50 and/or 52 away from the web 6. A washer 60 of any suitable material is carried by arm 36 over hole 58 in order to provide a sliding seal on top of the hole to prevent dust and lint getting into the switch box itself.

At the upper end of arm 36 there is provided an adjustable set screw 62 which is threaded through the end of the arm and clamped in adjusted position by means of a conventional lock nut as shown. The end of the set screw 62 bears against the switch arm 26 for actuation thereof if the bell-crank pivots in its mounting clevis 30 due to motion of the rollers 50 and 52 away from or toward the web 6.

It is to be noted that the adjustment of the screw 62 is such that the contacts of switch 18 are held open by arm crank 36-34-38 counterclockwise about its shaft 31, 36 when the rollers 50-52 are in normal contact with the flat top surface of the web 6. If, on the other hand, the rollers are lifted away from the web by the presence of the seam passing thereunderneath, this will move the bellthus permitting the 'contact arm 26 to move to the left (as viewed in FIG. 1) and thus permitting the rotary switch arm 24 to move clockwise in order to close the contacts of switch 1-8, switch 18 being of the type in which its contacts are normally closed when the switch arm 26 is in its normal unrestrained position.

In a manner similar to that described above for the bell crank 36-34-38 and its relationship to the switch 18, together with the rollers 50-52 and the swivel bearing 42, a similar bell crank is provided at the other end of the base and comprises the vertically extending arm 66, the hub 68 and the bearing shaft 70 for hub 68 to permit the bell crank to rock or pivot in the clevis 32. Arm 66 55a the other arm 72 of the bell crank are both screwed into the hub 68 and are held therein by means of the conventional lock nuts 74 and 76.

As in the other bell crank, arm 72 screws into the extension 78 of the swivel bearing 80 which houses the swivel ball 82 through which passes the shaft 84, the latter be- 4 ing held at its center portion within the swivel ball 82 by means of the collars 86.

At the ends of the shaft 84 there are mounted rollers 88 and 90 which serve the same function as the rollers 50 and 52.

Also, as in the other bell crank arrangement, there is provided a U-shaped snubbing or retaining means 92 for shaft 84, which is clamped to the extension 78 by means of the lock nut 94. As before, a slight clearance is provided between the outwardly turned ends of the retaining member 92 in order not to bind the shaft 84 against predetermined proper movement, but to prevent any motion thereof basically in the plane horizontal to the web 6, while permitting free upward and downward or swivel motion of the shaft 84 and thus the rollers 88 and 90 with respect to web 6. That is, each of the rollers '88 and 90 is prevented from moving in a direction longitudinal of the web 6.

Also, as in the previous bell crank arrangement, a hole 96 is provided in the base 10 through which passes the upright vertical arm 66 of the bell crank, the hole being large enough to permit free play of arm therein. A cover washer 98 is provided on the upright arm, which covers the hole 96. At the upper end of arm 66 there is provided an adjusting screw 100 which bears against the switch lever 22 and therefore serves the same function as the adjusting screw 62 for its switch.

Upon movement of the rollers 88 and 90 away from the web 6, the bell crank arm 66 will move to the right as viewed in FIG. 1, thus relieving the switch lever 22 permitting it to move in a counterclockwise direction. Such motion will rotate the rotary switch shaft 20 of switch 16 counterclockwise, to permit closing of the contacts.

(Switch 16 is similar to switch 18, and is of the type which has its contacts normally closed, but when the rollers 88 and 90 are in contact with the web 6, the switch contacts are open.)

T o enclose the switch members and switch arms, etc., a suitable box-like structure is provided in conventional manner including a top 104, sides 106, and ends 108. An on-off toggle switch may be provided in one of the ends 108 as shown for the purpose of connecting and disconnecting the switches from the rest of the control structure which is not part of this invention.

Electrically, the contacts of the switches 16 and 18 are so connected so that the switches are in parallel with each other, and switch 110 is serially connected to the switches 16 and 18. That is, upon the actuation of either switch 16 or 18 by a motion of its respective bell crank operator, that switch will close its contacts, and closing of the contacts will operate associated control apparatus through toggle switch 110.

The operation of the apparatus is as follows:

As has been mentioned above, one of the features of the apparatus is that the occurrence of a slub passing beneath one roller of the apparatus will not actuate the switches to cause nuisance strip-outs. The explanation of this is that the adjusting screws 62 and 100 are so set that when a slub occurs in the web 6 and passes beneath, for example, the roller 90 and the anvil or plate 12 on bed 14, this will raise the roller above the height of the top surface of the web 6. However, the other roller 88 has not been so raised with the result that the Shaft 84 is tilted and this moves the swivel joint 80 in an upward direction a distance approximately one-half of the height of the slub. The adjusting screw 100 is adjusted so that this amount of movement of the bell crank will not move the rotary switch arm 20 sufliciently to close the contacts of switch 16. Similarly, when the slub passes under the roll 52, the adjusting screw 62 is so set that the motion of the bell crank caused by the tilting of the shaft 46 will not be sufiicient to actuate the switch 18.

However, assuming that a seam such as that shown by numeral 112 passes beneath the apparatus 2. As it so passes, it will lift, first of all, the rollers 88 and 90 simultaneously or nearly at the same time, and this simultaneous lifting of both rollers will lift the swivel joint the full height of the seam, and will rotate the bell crank approximately twice as far as was the case when the slub passed under roll 90 alone. The set screw 100 can be set so that sufficient rotation will be imparted to the rotary switch shaft 20 to close the contacts of switch 16. A similar functioning takes place when the seam passes under rollers 50 and 52 and actuates the associated swivel joint 42 and bell crank.

However, mentioned above is the feature that the rolls 88 and 90, and the rolls 50 and 52, should have to move a distance away from the web 6 which is greater than the thickness of the seam 112. To provide this, the adjusting screws 100 and 62 are first so adjusted that mere passage of the seam 112 beneath the respective pairs of rollers will just cause closing of the contacts of the respective switches 16 and 18. The adjusting screws are then backed-off a short distance (determined by trial and error but within the skill of the art) that this movement of the bell cranks will not close the contacts. It will thus require further motion of the respective pair of rollers in a direction away from the web 6 for this actuation.

That this occurs is due to the fact that the web 6 is generally travelling at fairly rapid speed across the plate 12. Therefore, when the seam 112 strikes the rollers 88 and 90, it will cause the rollers to jump in an upward direction, and due to the momentum thus imparted to the rollers, the shaft 84, and the entire bell crank structure associated with these rollers, the rollers will rise to a point greater than the thickness of the seam itself. The adjusting screw 100 is then adjusted so that with this upward impulse given to the rollers, the switch 16 is actuated to close its contacts at about the top of this throw. In similar manner, the adjusting screw 62 is adjusted to cause actuation of the switch 18 about at the top of the throw of the rollers 50 and 52.

With the double bell crank construction shown, a further advantage of the apparatus is obtained as follows: Assuming that under the manual control of the operator, the web of cloth has been stopped so that a seam occurs just to the left of the rollers 88 and 90. Now, when the web is first started up, it obviously starts from the Zero velocity and therefore, when the seam passes 'beneath the rollers 88-90, the above-mentioned impulse will not be imparted to the rollers and the switch 16 will not close its contacts. However, by the time the seam has passed beneath the apparatus and has come to the rollers 50 and 52, it will be travelling at a speed sufficient to throw rollers 50 and 52 enough to actuate the switch 18. Thus, by the provision of two switches, a safety factor is provided that renders the machine always operative regardless of where a seam is at the time the web is started.

In the particular embodiment, vertically oriented switch arms are shown, actuable by a bell crank. It is within the skill of the art in the light of the teaching of this case, to have the switch levers 22 and 26 horizontal, to be actuated by horizontal bell crank arms attached to hubs 34 and 68. Also, instead of bell cranks, a pair of vertical slide mechanisms can be used, one at each end of bed 10, with the lower ends of the slides holding the respective swivel joints, and the upper ends operating horizontally-oriented switch levers.

In view of the above it will be seen that the several objects of the invention are achieved and other advantageous results attained.

It is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it to be understood that the phraseology or terminology employed therein is for the purpose of description and not of limitation.

As many changes could be made in the above con structions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings, shall be interpreted as illustrative and not in a limiting sense, and it is also intended that the appended claims shall cover all such equivalent variations as come within the true spirit and scope of the invention.

Having described the invention, what is claimed is:

1. Apparatus for detecting an elongated thickened portion in a moving web of material comprising:

a base positioned adjacent a surface of the web;

switch means mounted on the base;

movable means mounted on the base and adapted to actuate the switch means on motion thereof due to a first occurrence of said thickened portion;

swivel means mounted on said movable means adjacent said web;

a shaft carried at its central portion by the swivel means and extending across the web in a direction at an angle to the direction of motion of the web; and

a pair of feeler means mounted one at each end of said shaft and adapted to be in contact with said web, whereby motion of both of the feeler means away from the web due to contacting said thickened portion will cause actuation of the movable means an amount sufficient to actuate the switch means, but motion of only one of said feeler means in a direction away from the web will not actuate the switch means.

2. The apparatus of claim 1 in which said movable means and said switch means are so positioned with respect to each other that the motion of the movable means required to actuate the switch means is greater than the thickness of said thickened portion.

3. The apparatus of claim 1 in which said movable means comprises a bell crank rotatably mounted on the base and having one arm positioned to actuate the switch means upon rotary motion of the crank, and a second arm extending at an angle toward said web, said swivel means being carried by the second arm at the end thereof adjacent the web.

4. The apparatus of claim 3 in which the amount of motion of each of said feeler means of a pair thereof simultaneously in a direction away from the web, which is necessary to actuate the respective switch means, is no less than the thickness of said thickened portion.

5. The apparatus of claim 1 in which said feeler means comprise rollers rotatably mounted on said shaft.

6. The apparatus of claim 4 in which said feeler means comprise rollers rotatably mounted on said shaft.

7. The apparatus of claim 1 including a second switch means mounted on the base adjacent the web; second movable means mounted on the base and adapted to actuate the second switch means on motion thereof due to a second occurrence of said thickened portion; second swivel means mounted on the second movable means adjacent the web; a second shaft carried at its central portion by the second swivel means and extending across the web in a direction at an angle to the direction of motion of the web; and a second pair of feeler means mounted one at each end of the second shaft and adapted to be in contact with the web, whereby motion of both of the second feeler means away from the web due to contacting said thickened portion will cause actuation of the second movable means an amount suflicient to actuate the second switch means, but motion of only one of the second feeler means in a direction away from the web will not actuate the second switch means.

8. The apparatus of claim 7 in which said second movable means comprises a second bell crank rotatably mounted on the base and having one arm positioned to actuate the second switch means upon rotary motion of the crank, and a second arm extending at an angle toward the Web, the second swivel means being carried by the second arm of the second bell crank at the end thereof adjacent the web, and said second pair of feeler means comprise rollers rotatably mounted at the ends of said second shaft.

9. The apparatus of claim 8 in which the amount of motion of each of said rollers in a direction away from the web approximately simultaneously, which is necessary to cause actuation of the second switch, is no less than the thickness of said thickened portion.

10. The apparatus of claim 9 in which said first and second switch means are connected in parallel with each other.

11. The apparatus of claim 1 including means positioned with respect to said shaft for preventing motion of either of said feeler means about the swivel means generally in a direction longitudinal of the Web.

12. The apparatus of claim 8 including means positioned with respect to each of said shafts for preventing motion of any of said rollers generally in a direction longitudinal of the web.

References Cited UNITED STATES PATENTS 2,523,184 9/1950 Beall 20061.14 XR 'ROBERT K. SCHAEFER, Primary Examiner M. GINSBURG, Assistant Examiner agg I UNITED STATES PATENT GFFICE CERTIFICATE OF CORRECTION Patent No.3,514,558 Dated May 26, 1970 Inventor-(s) Ralph L. Davidson It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

[ In the specification, column 3, lines 52-62,

should read as follows:

36 when the rollers 50-52 are in normal contact with the flat top surface of the web 6. If, on the other hand, the rollers are lifted away from the web by the presence of the seam passing thereunderneath, this will mOv the bellcrank' 36 -34-38 c0unterc1ockwise about its shaft 31, thus ermitting the contact arm 26 to move to the left (as I viewed in Fig. l) ahd thus permitting the rotary switch arm 24 to move clockwise in order to close the contacts of switch 18, switch l8 being of the type in which its contacts are normally closed when the switch arm 26 is in its normal unrestrained position.

SIGNED AND SEALED a SEP 291970 a 6131,) p mm s. as. Edward H. Fletcher, Ir. oomasim or Pant 

